This was designed for the typewriter contest. All I could think of was all the typing exercises I did when I learnt to type. And that got me thinking about "The quick brown fox jumps over the lazy dog". And that lead me to look at other pangrams (sentences that include all letters of the alphabet). And when I went looking for some more, most of them included how many letters they had in the description, which kind of then lends itself to ordering them in size, and lo and behold you have a pattern...